Works around Future Topics section, by querying the RSS feed instead

Topic votes aren't exposed through the RSS feed, so as a temporary (permanent?) work around, I added a "Vote" button that will link to the topic on idea scale.

Will look at other options for getting the current vote totals, as a separate issue. (Would like to avoid scraping if somehow possible).

IdeaScale repository rewritten to use the syndication feed instead of the rest api. All tests still passing.